iio:adc:ad7923: Add support for the ad7904/ad7914/ad7924

The ad7924 is software compatible with the ad7923. The ad7904 and ad7914 are the
8 and 10 bit version of the ad7924.

While we are at it also drop the "with temperature sensor" from the Kconfig
entry, since the chips do not have a temperature sensor.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Patrick Vasseur <patrick.vasseur@c-s.fr>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/Kconfig

@@ -31,13 +31,13 @@ config AD7298
 	  module will be called ad7298.
 
 config AD7923
-	tristate "Analog Devices AD7923 ADC driver"
+	tristate "Analog Devices AD7923 and similar ADCs driver"
 	depends on SPI
 	select IIO_BUFFER
 	select IIO_TRIGGERED_BUFFER
 	help
-	  Say yes here to build support for Analog Devices AD7923
-	  4 Channel ADC with temperature sensor.
+	  Say yes here to build support for Analog Devices
+	  AD7904, AD7914, AD7923, AD7924 4 Channel ADCs.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7923.

drivers/iio/adc/ad7923.c

 /*
- * AD7923 SPI ADC driver
+ * AD7904/AD7914/AD7923/AD7924 SPI ADC driver
  *
  * Copyright 2011 Analog Devices Inc (from AD7923 Driver)
  * Copyright 2012 CS Systemes d'Information
@@ -70,7 +70,18 @@ struct ad7923_state {
 	__be16				tx_buf[4];
 };
 
-#define AD7923_V_CHAN(index)						\
+struct ad7923_chip_info {
+	const struct iio_chan_spec *channels;
+	unsigned int num_channels;
+};
+
+enum ad7923_id {
+	AD7904,
+	AD7914,
+	AD7924,
+};
+
+#define AD7923_V_CHAN(index, bits)					\
 	{								\
 		.type = IIO_VOLTAGE,					\
 		.indexed = 1,						\
@@ -81,18 +92,38 @@ struct ad7923_state {
 		.scan_index = index,					\
 		.scan_type = {						\
 			.sign = 'u',					\
-			.realbits = 12,					\
+			.realbits = (bits),				\
 			.storagebits = 16,				\
 			.endianness = IIO_BE,				\
 		},							\
 	}
 
-static const struct iio_chan_spec ad7923_channels[] = {
-	AD7923_V_CHAN(0),
-	AD7923_V_CHAN(1),
-	AD7923_V_CHAN(2),
-	AD7923_V_CHAN(3),
-	IIO_CHAN_SOFT_TIMESTAMP(4),
+#define DECLARE_AD7923_CHANNELS(name, bits) \
+const struct iio_chan_spec name ## _channels[] = { \
+	AD7923_V_CHAN(0, bits), \
+	AD7923_V_CHAN(1, bits), \
+	AD7923_V_CHAN(2, bits), \
+	AD7923_V_CHAN(3, bits), \
+	IIO_CHAN_SOFT_TIMESTAMP(4), \
+}
+
+static DECLARE_AD7923_CHANNELS(ad7904, 8);
+static DECLARE_AD7923_CHANNELS(ad7914, 10);
+static DECLARE_AD7923_CHANNELS(ad7924, 12);
+
+static const struct ad7923_chip_info ad7923_chip_info[] = {
+	[AD7904] = {
+		.channels = ad7904_channels,
+		.num_channels = ARRAY_SIZE(ad7904_channels),
+	},
+	[AD7914] = {
+		.channels = ad7914_channels,
+		.num_channels = ARRAY_SIZE(ad7914_channels),
+	},
+	[AD7924] = {
+		.channels = ad7924_channels,
+		.num_channels = ARRAY_SIZE(ad7924_channels),
+	},
 };
 
 /**
@@ -245,6 +276,7 @@ static int ad7923_probe(struct spi_device *spi)
 {
 	struct ad7923_state *st;
 	struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
+	const struct ad7923_chip_info *info;
 	int ret;
 
 	if (indio_dev == NULL)
@@ -258,11 +290,13 @@ static int ad7923_probe(struct spi_device *spi)
 	st->settings = AD7923_CODING | AD7923_RANGE |
 			AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS);
 
+	info = &ad7923_chip_info[spi_get_device_id(spi)->driver_data];
+
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->dev.parent = &spi->dev;
 	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->channels = ad7923_channels;
-	indio_dev->num_channels = ARRAY_SIZE(ad7923_channels);
+	indio_dev->channels = info->channels;
+	indio_dev->num_channels = info->num_channels;
 	indio_dev->info = &ad7923_info;
 
 	/* Setup default message */
@@ -324,7 +358,10 @@ static int ad7923_remove(struct spi_device *spi)
 }
 
 static const struct spi_device_id ad7923_id[] = {
-	{"ad7923", 0},
+	{"ad7904", AD7904},
+	{"ad7914", AD7914},
+	{"ad7923", AD7924},
+	{"ad7924", AD7924},
 	{}
 };
 MODULE_DEVICE_TABLE(spi, ad7923_id);
@@ -342,5 +379,5 @@ module_spi_driver(ad7923_driver);
 
 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 MODULE_AUTHOR("Patrick Vasseur <patrick.vasseur@c-s.fr>");
-MODULE_DESCRIPTION("Analog Devices AD7923 ADC");
+MODULE_DESCRIPTION("Analog Devices AD7904/AD7914/AD7923/AD7924 ADC");
 MODULE_LICENSE("GPL v2");